A star tracker determines the bearing and elevation of one or more known stars. Information from two or more known stars can yield the position of the star tracker and thus can provide position data to an associated navigation system as may be used, for example, on maritime craft, aircraft, spacecraft, or satellites. Many star trackers comprise telescopes that make use of sun shades to shade the star tracker field-of-view from stray light coming from the Sun, Earth, or Moon, to provide a view of needed reference stars that is unadulterated by out-of-field radiation.